1. Field of the Invention
The present invention relates to a method of manufacturing from a plastic material or a superplastic metal material a press-formed product, for example, a formed product of complicated shape such as a golf club head or an automobile component, specifically, a formed product which is shaped to have a base portion and a projecting portion in a direction different from the base portion.
2. Description of the Prior Art
Forging has heretofore been known as a method of forming a complicated shape employing a metal material. Forging is a method of compressing a material to destroy its cast structure and compress its harmful defects, thereby improving the mechanical properties of the material and producing a product of desired shape. Forging is used in various applications.
However, if a formed product is to be produced by forging, a preform which is conformed to the shape of the formed product in advance is needed. As the shape of a product becomes more complicated, the shape must be modified gradually in more forging steps, so that multistage production is needed. Particularly if a rapidly-solidified alloy material is employed as a material for the formed product, the superior characteristics of the rapidly-solidified alloy material are easily affected by heat during the formation of the aforesaid preform and multistage formation, with the result that crystal grains become coarse and the superior features of the rapidly-solidified alloy material are impaired.